Heart failure (HF) is at epidemic proportions, affecting 5 to 6 million patients in the US. Despite the myriad of major advances in cardiology, the prognosis for patients with severe, medically refractive HF is exceedingly poor. Approximately 250,000 deaths occur annually with the majority of these individuals enduring an increasingly impaired quality of life accompanied by significant economic and personal losses due to recurrent hospitalizations. Because the number of available heart donors (˜2,200/year) has not increased over the last decade, there is an enormous and expanding gap between the medical need for transplant and a woefully low supply.
Left ventricular assist devices (LVAD), mechanical circulatory support systems, have developed tremendously from the large pulsatile devices of the last decade to the third generation continuous flow devices of today. The reduced size and power requirements of today's axial-flow instruments has allowed LVADs to become a therapeutic option for patients with intractable HF, whether as a bridge to transplantation (BTT) or a destination therapy (DT). According to the INTERMAS 4th Annual report for reporting US institutions, the number of LVADs placed as a BTT or DT increased from 61 in 2006 to 906 in 2010, and the number continues to increase. While LVAD placement offers considerable hope and benefit to many patients with severe HF, their successful clinical implementation remains a learning process, even regarding patient selection. Moreover, LVADs are associated with well known complications, including gastrointestinal bleeding, driveline infections, and thrombosis. Although GI bleeding and infection can be readily diagnosed and treated, intra-pump thrombosis cannot be easily diagnosed, and treatment approaches are too risky to administer to patients without a clear diagnostic mechanism to rely upon. For instance, the use of antiplatelet agents or thrombolytics for suspected intra-pump thrombosis is associated with very high risks of death with reports of up to 50% death in patients treated with fibrinolytics. Similarly, removal of LVADs in this cardiovascularly comprised population is associated with a 30 to 50% risk of death in one year. As such, the lack of an easy and reliable diagnostic tool capable of detecting intra-pump thrombosis has so far limited the wider adoption of these devices.
Therefore, there is a need for a rapid, easy, and quantitative method of assessing intra-pump thrombosis.